6 ton Climastermaster on retrofit duckwork ?

[oldkars56]

Hi, I just had a 6 ton Climatemaster installed using existing duckwork , I have two story 2600 sf .. I had two systems before now I have one with zone dampers.. My supply trunk on the downstairs is 16x8 and 25 feet going one direction and 18 ft going the other right off the plenum .. The system is noisy and whisltes , they added something to it that doesn’t make since to me (I included a pic of it ).
When the owner of the company bid the job he said my duckwork will work fine ( his installer says it to small and they didn’t bid the job to replace any duckwork ) .. I purchased this system to be efficient and save money , will undersized duct work effect my operating cost .. They ran a 10 round pipe out of my supply directly back into the cold air return at the unit , I have never seen anything like it on a furnace ..
Im at a loss for words wondering what I should do to correct the potential problem .. also my water was not tested and I am on a well with hard water 425 gpm hardness... in Climatemaster water quality guide says it should be less than 10gpm per million .. contractor says doesnt mean anything .. any suggestions would be welcome

[beenthere]

Could be wired wrong and not running in first stage only when it should. Probably need a fair amount of duct work alteration.

Your first floor duct, doesn't sound large enough for 3 tons(1200CFM), and a 10" bypass is only good to recirc about 2 tons of air flow(800CFM).

Call the contractor and tell him about the noise.

[catmanacman]

sounds like your contractor should have done his home work before installing the unit .did he do a load calculation to verify that you needed 6 tons of hvac for 2600 square feet. I'm betting not, it is stupid to dump supply into the return

[oldkars56]

I have questioned contractor and he is very defensive . I have 40 days of electric bill and it is $400 ,,and this has been the mildest Nov /Dec in years .
Once I subtract the geo kilawatt usage on the seperate meter , it appears that my normal electric usage has gone up and I dont understand why I am not doing anything different. Contractor said by using the bypass it will be more efficient.. I question that .. Don:gah:

[beenthere]

Won't be more efficient. A bypass is used when a single zone is not large enough to move the min amount of air that the unit requires.

[thermojohn]

Six tons of air in a 2,600 ft2 space? Home or business? How insulated is the structure? What was the capacity of the other two systems? What is the area of the smallest zone? How many zones do you have? Is this a two speed unit? They work well with zoning.

With six tons air, and tied into a zone system type control, you have to have a bypass loop to relieve the pressure when all zones are not calling, or you suffer terrible noise fatigue quickly, and create other problems with the system. I hope he didn't forget to install the bypass damper. :gah: If the damper is there, is it barometric, or motorized?

Pictures of the set-up would do a world of good here. Your separate meter is set up how?

So many questions..... It is difficult to solve these problems without going on-site, and getting a feel for what is really going on here.

Curious.... How many bids did you get, and where on the scale did this contractor fit in relating to price?

[beenthere]

Not unusual for a 2 stage geo to be sized for the heat loss.